Gravity chemical clarification system



Sept. 22, 1942.

A. M. RAY

GRAVITY CHEMICAL CLARIFICATION SYSTEM umrmotm Filed Sept. 24, 1940 INVENTOR 7717110 JVl- R WITNESSES My): ATTQRN EYS Patented Sept. 22, 1942 GRAVITY CHEMICAL CLARIFICATION SYS TEM

Arthur M. Ray, Helena, Mont.

Application September 24, 1940, Serial No. 358,107

7 Claims. (01. 196-15) This invention relates to apparatus and methods for gravity chemical clarification of dry cleaning solvents, and has for an object to provide an improved construction which is simple and which may be used either intermittently or continuously.

Another object of the invention is to provide an apparatus for cleaning a dry cleaning solvent with a structure wherein the clean solvent, the dirt or sludge, and the cleaning solution may be all drawn off at the same time or at different times and at different points.

A further object of the invention is to provide a cleaning apparatus in which dry cleaning solvent is cleaned in a preliminary way and then is cleaned in a final Way through the action of gravity.

In the accompanying drawing, the figure is a view partly in elevation and partly in section showing the apparatus for cleaning solvents, the same disclosing an embodiment of the invention.

Referring to the accompanying drawing by numerals, I indicates a large tank which may be termed a separating tank, 2 a small tank which may be termed a mixing tank, and 3 a medium sized tank which may be referred to as the third tank. These tanks are all arranged in vertical alignment. As desirable proportions, tank I is of one hundred and fifty gallons capacity, tank 3 of fifty gallons capacity, and tank 2 of twenty-five gallons capacity. While the proportions just mentioned are desirable, they are not at all essential so that they may be varied widely without departing from the spirit of the invention.

Associated with the tank I, is a supply tank 4, a sludge tank 5, and an auxiliary separating tank 6, as well as a storage tank 1. Preferably tank I is cone-shaped at the bottom and preferably tank 2 is cone-shaped at the top and bottom. A clean-out valve 8 is arranged at the bottom of tank 2 and at the top a pipe 9 connects the upper end of tank 2 to the bottom end of tank I. A draw-off pipe i is connected with pipe 9 and is provided with a valve H, whereby sludge or liquid matter may be drawn from pipe 9 whenever desired. Pipe IO discharges into the sludge tank 5, which is removably mounted on a suitable support l2 and which is provided with drawoif valves I3 and M. A pipe I connects the bottom of tank 4 with the top portion of tank 3 and has a pump it interposed in its length. Pump 16 maybe of any desired kind and is adapted to pump liquid from tank} into tank'3;

This pumping action may be continuous while 5 Caustic potash do the device is in use or may be intermittent. Usually the pump is actuated intermittently so that after a certain supply of the solvent cleaning solution I! is pumped into tank 3 no additional solution is needed for some time. A pipe l8 directs dirty solvent or sludge-laden'cleaning solvent from a dry cleaning washer or other place to the upper part of tank 3, into which it discharges. The dirty solvent from pipe l8 mixes -with the solvent cleaning solution I! in tank 3 and moves with this solution downwardly to near the bottom of tank 2 through pipe l9. Pipe I9 has a reduced or constricted portion 20, so that fluid will move rather slowly through the lower part of pipe I 9 and discharge through the nozzle or reduced end 2| at a comparatively slow speed. Nozzle 2| may be removed and a difierent size one used at any time. I It will be noted that the pipe 49 extends through tank I, through pipe 9, and into tank 2, though, if desired, pipe l9 could be at one side of tanks l and 2 and the bottom of pipe I9 brought in from the exterior of tank 2, so that it will discharge at the same point, as shown in the accompanying drawing. However,

the arrangement disclosed is preferable as it allows gravity to act readily on the various liquid solutions so that the device may be actuated as an intermittent or continuous cleaning and separating construction. The dry cleaning solvent may be any suitable dry cleaning solvent which is a derivative of petroleum. The solvent which has actually been used is known in the industry as Dixie Stoddards Specifications. Also the solvent which has been used is made by Standard Oil Company, Socony Vacuum and Shell Oil companies under such names as Salvarsol and Petrosol. The solvent is a refined petroleum and is somewhat similar to a high grade of gasoline.

The method and apparatus of the present invention are intended to clean the solvent after the solvent; has become dirty through the cleaning of clothes and other articles.

The solution I1 is an alkali solution and various proportions of alkali and water may be used with good results. However, the best results have been secured by the use of the following proportions:

Water gallons Caustic soda pounds 50 Huron alkali do 50 Soda ash do 25 Borax do 25 When these ingredients are properly mixed the solution should have a specific gravity of 16 on an alkali hydrometer. While the specific gravity 16 is the most desirable, either higher or lower gravities may be used without departing from the spirit of the invention, as gravities as low as 12 and as high as 21 have been used with good results.

The cleaning solvent, which is a petroleum derivative, has a lower specific gravity than the solution I1 and the dirt or sludge has a higher specific gravity than the cleaning solvent but a lower specific gravity than the alkali solution I'I. By reason of these facts, when the mixture from tank 3 is flowing into tank 2, tank I will gradually fill and in doing so there will be an automatic separation by reason of the difference in specific gravity so that the upper part and, in fact, most of tank I will be filled with clean solvent and most of tank 2 will be filled with alkali solution while the sludge will fill pipe 9 and the cone-shaped bottom of tank I It will be understood, of course, thatv a small amount of solution I! and a small amount of solvent will remain in the sludge as it is drawn off and discharges into the tank 5. After it is allowed to remain in the sludge tank for some considerable time, as for instance, an hour or more, there will be a decided separation so that the valve I4 may draw off the solvent in a. substantially clean state and the valve I3 may draw off the alkali solution IT in a substantially clean condition. After this has been done, tank 5 is preferably removed from the support I2 and the sludge is thrown away. The tank 5 is then cleaned and again placed in position. This cleaning action may take, place once a day or once a week according to how often the device is used.

Naturally the solvent near the top of tank I will be the cleanest, but this one cleaning action will not completely clean the solution though it will be clean enough for further use in a dry cleaning washer if desired. However, as shown in the drawing, there are provided four outlets or draw-01f valves 22. These valves are connected t a down pipe 23 which discharges into the bottom of the auxiliary cleaning or separating tank 6. A clean-out valve 24 is arranged at the bottom of tank 6 so as to clean the same Whenever desired. Some of the alkali solution I! is placed in tank 6 with a surface at approximately line 25. If the upper valve 22 is opened all the partially cleaned solution in tank I above the valve will flow downwardly and intov the bottom tank 6. The partially cleaned solution will pass upwardly through the solution 25 and as it passesfarther up it will automatically separate so that after a while a sludge zone 26 will be provided similar to the sludge Zone 21 at the bottom of tank I. The upper zone 28 in tank 6 contains a completely cleaned solvent which is directed by a pipe 29 into a storage tank 1. From tank 1 the clean solvent may be drawn off from time to time and used as desired,

The main cleaning action takes place in tank I. By using tank 6 a cleaner solution may be secured as tank 6 produces a second cleaning action. A sludge draw-off valve 30 is provided for tank 6 so that the sludge may be drawn off from time to time, while the clean solvent will automatically flow from tank 6 as fast as it reaches the pipe 29.

Once a, day, once a week, or at other spaced intervals, the solution 25' should be drained through valve 24 and a new supply provided.

The liquid in tank 2 may be drawn off at any time but usually it is drawn off at long intervals because there is a continuous new supply of solvent and solution directed to the lower part of this tank. If the tanks I and 2 are filled and left standing for some time, a desired separation will be secured and all the valves 22 may be opened and practically all the solvent discharged into tank 6 and thence into storage tank I. Where the operation is continuous or substantially continuous, usually only the top valve 22 is opened so that the cleanest part of the solvent will discharge into tank 6 in a continuous stream. Glass tubes 3|, 32 and 33 are provided so that the worker may readily observe the color of the solution in tanks I and 3 and thereby know when it is necessary to operate pump IE to supply more of the solvent cleaning solution.

I claim:

1. A gravity chemical clarification system for cleaning a dry cleaning solvent including a separating tank, a mixing tank positioned below the separating tank, conduit means providing free communication between the bottom of the separating tank and the top of the mixing tank, a third tank arranged above the separating tank, conduit means leading from the bottom of the third tank to near the bottom of the mixing tank, means for directing dirty cleaning solvent into said third tank at the top thereof, means for directing a solvent cleaning solution into said third tank at the top thereof whereby said dirty solvent and said cleaning solution will be discharged through said second conduit means into said mixing tank near the bottom, means for draining off solvent from said separating tank, and means for drawing off sludge from between said separating tank and saidmixing tank.

2. A device as set forth in claim 1, characterized by a sludge tank positioned to receive the sludge as it is drawn off, a valve at the bottom of said sludge tank for drawing. off the solution settling out of said sludge, and a valve intermediate the top and bottom of said sludge tank. for drawing off any solvent that settles out of the sludge,

3. A device as set forth in claim 1, characterized by a fourth tank, conduit means for directing solvent from said separating tank to the bottom of said fourth tank, whereby solvent from said separating tank must pass through solution placed in said fourth tank for a second cleaning action, means intermediate the height of said fourth tank for drawing off sludge therefrom and means adjacent the top for drawing off second cleaned solvent.

4.. A device as set forth in claim 1, wherein said first conduit means has a restricted part intermediate its length to cause fluid from the third tank to How to the bottom of the mixing tank gently.

5. A device of the character described comprising a mixing tank, a separating tank, a third tank, all of said tanks being arranged in vertical alignment, conduit means connecting the bottom of the separating tank and the top of the mixing tank, a pipe extending from the bottom of said third tank through said separating tank and said conduit means to near the bottom of the mixing tank for directing liquid from the third tank into the mixing tank, means" for supplying a solvent cleaning solution to said third tank, means for directing dirty cleaning solvent to said third tank, means for drawing off said '7. In a gravity chemical clarification system, a mixing tank having a conical upper end, a separating tank having a conical bottom above said mixing tank, a short conduit establishing communication between the interiors of said tanks, a gravity feed for the matter to be clarified leading downwardly into said mixing tank in proximity to the bottom thereof, and means connected with said conduit for drawing off sludge 10 from the bottom of said separating tank.

ARTHUR M. RAY. 

